Photodehydrocyclizations in stilbene-like compounds. X. Rearrangements in the photocyclization of 4,5-diphenyltriphenylene and 4,5-diphenylphenanthrene
Synthesis of sterically hindered 4,5-diarylphenanthrenes <i>via</i> acid-catalyzed bisannulation of benzenediacetaldehydes with alkynes
作者:Yuanming Li、Akiko Yagi、Kenichiro Itami
DOI:10.1039/c9sc00334g
日期:——
The synthesis of stericallyhindered phenanthrenes via acid-catalyzed bisannulation reaction is described. Treatment of 1,4-benzenediacetaldehyde with terminal aryl alkynes in the presence of B(C6F5)3 provides 4,5-diarylphenanthrenes in good yields with excellent regioselectivity. The use of internal alkyne substrates enabled the synthesis of stericallyhindered 3,4,5,6-tetrasubstituted phenanthrenes
描述了通过酸催化的双环合成反应合成位阻菲。在B(C 6 F 5)3存在下用末端芳基炔烃处理1,4-苯二乙醛可提供高收率的4,5-二芳基菲,具有出色的区域选择性。内部炔烃底物的使用使得能够合成显示出增加的主链螺旋度的空间受阻的3,4,5,6-四取代菲。此外,通过炔烃与1,3-苯二乙醛或1,3-苯二乙醛的反应可制得1,5-二取代,1,8-二取代,1,2,5,6-四取代和1,2,7,8-四取代的菲。 1,2-苯二乙醛二甲硅烷基缩醛。
Photocyclisations of 1,4-diarylbut-1-en-3-ynes. Part III. Scope and limitations of the reaction
作者:Alois H. A. Tinnemans、Wim H. Laarhoven
DOI:10.1039/p29760001115
日期:——
The photoreactivity of a large series of diarylbutenynes has been studied in order to establish the scope of this photocyclisationreaction. The conditions for an optimal yield of photocyclisation products are discussed. On addition of iodine to the butenyne solution, irradiation gives rise to iodo-derivatives of the normal cyclisation products, whereas in the presence of iodine and with benzene as